The present invention relates to a bonding apparatus and, more particularly, to a lamination apparatus and a lamination method using the same.
Generally, metal sheets are bonded by means of brazing, soldering, plasma welding or laser welding according to the kinds of metals.
Welding is wherein metal sheets are bonded by solidifying bonding surfaces of the metal sheets after partially fusing the bonding surfaces. Plasma welding or laser welding should be used to fully seal the interior defined by the bonding. Unfortunately, plasma welding and laser welding incur much higher costs than soldering. Namely, the plasma welding and the laser welding have a low economical efficiency.
Soldering is wherein metal sheets are bonded by solidifying a bonding material after fusing the bonding material having a lower fusing point than the metal sheets to flow between the metal sheets bonded by a capillary phenomenon. The soldering is performed at a temperature of 430 degrees centigrade or lower. Unlike the soldering, brazing is performed at a temperature of 430 degrees or higher. Soldering and brazing are selectively applied according to the kinds of metal sheets.
When metal sheets are bonded by means of soldering, there is a limitation in selecting a bonding material because the bonding material should have a lower fusing point than the metal sheets. Further, bonding materials may be different in thickness and become porous to drop in density. Since the soldering is performed in the air, the bonding materials are apt to be oxidized. For these reasons, bonding force of a bonding material may diminish considerably.